Tiagabine suppresses pentylenetetrazole-induced seizures in mice and improves behavioral and cognitive parameters by modulating BDNF/TrkB expression and neuroinflammatory markers

Unraveling the neuroprotective effect of perampanel and lacosamide combination in the corneal kindling model for epilepsy in mice

BACKGROUND

Scientific evidence to guide clinicians on the use of different antiseizure drugs in combination therapy is either very limited or lacking. In this study, the impact of lacosamide and perampanel alone and in combination was tested in corneal kindling model in mice, which is a cost-effective mechanism for screening of antiseizure drugs.

METHODS

The impact of lacosamide (5 mg/kg) and perampanel (0.125 mg/kg) alone and their combination was tested in corneal kindling process (3-mA current for 3 s applied twice daily for consecutive 12 days) in male BALB/c mice. Post-kindling, mice were subjected to a battery of behavioral tests assessing anxiety, memory, and depression-like behaviors. Brain tissues were then harvested for analysis of oxidative stress biomarkers.

RESULTS

Our results showed that the combination therapy of lacosamide and perampanel was more effective in reducing seizure progression than monotherapy of these drugs. Animals treated with combination therapy showed significant behavioral improvements, as reduced anxiety and depression were noticed, and their cognitive abilities were notably better compared to animals of all other groups. Moreover, biochemical assays of isolated brains from combination-treated group revealed lesser amount of oxidative stress. In addition, outcomes of dual regime were comparable to the phenytoin in seizure control but showed superior benefits in mitigation of kindling-prompted behavioral dysfunction and oxidative stress.

CONCLUSIONS

This study suggests that the lacosamide and perampanel combination therapy worked noticeably better in halting the corneal kindling process in mice and improved the epilepsy-associated psychiatric disorders that might be due to antioxidant effects of both drugs.

Co-administration of coenzyme Q10 and curcumin mitigates cognitive deficits and exerts neuroprotective effects in aluminum chloride-induced Alzheimer's disease in aged mice

Aluminum chloride (AlCl3), a known neurotoxic and Alzheimerogenic metal disrupts redox homeostasis which plays a pivotal role in pathophysiology of neurodegenerative disorders, particularly cognitive decline. The current study was designed to unveil the long-term neuroprotective outcomes and efficacy of CoQ10 and curcumin low dose (100 mg/kg each) combination in 18-months old geriatric male Balb/c mice subjected to AlCl3-prompted memory derangements (200 mg/kg in water bottles) for 28 days. The neuroprotective properties driven by antioxidant mechanisms were assessed via observing cellular pathology in key-memory related brain regions including the cornuammonis (CA3 and DG) and cortex 2/3 layer. Our outcomes revealed that AlCl3 exposure significantly reduced spatial learning and memory. In contrast, CoQ10 and curcumin combinatorial regime markedly mitigated cognitive deficits Vs. individual high-dose in AlCl3-treated animals as demonstrated by their improved performance in neurobehavioral tests such as the Y-maze, novel object recognition, passive avoidance and Morris-water maze test. Additionally, CoQ10 and curcumin co-administration restored redox balance by significantly reducing the levels of oxidative stressor (MDA) and increasing the anti-oxidant capacity (SOD,GPx). AchE is an enzyme involved in acetylcholine breakdown which negatively impacts acetylcholine levels and memory function. AlCl3 exposure elevated AchE levels in mice brains vs. treatment. This neurochemical alteration was notably reversed in the dual-treatment group. Furthermore, CoQ10 and curcumin ameliorated AlCl3-induced neurotoxicity by preserving neuronal cytoarchitecture in both cortical and hippocampal regions. In conclusion, CoQ10 and curcumin combination might attenuate memory loss induced by AlCl3-intoxication via restoring aberrant AchE activity, enhanced anti-oxidant defenses and salvaging the deleterious neuronal damage.

Geraniol Ameliorates Pentylenetetrazol-Induced Epilepsy, Neuroinflammation, and Oxidative Stress via Modulating the GABAergic Tract: In vitro and in vivo studies

Introduction

Geraniol (Ger), a monoterpene, is a common constituent of several essential oils. This study explored the anticonvulsant effect of Ger in-vitro using nerve growth factor (NGF) prompted PC12 cell injured by Glutamate (Glu) and in-vivo using Pentylenetetrazole (PTZ)-induced kindling through the GABAergic pathway.

Materials

To assess the effect of Ger on NGF prompted PC12 cells injured by Glu, Ger at concentrations of 25, 50, 100, 200 and 400 μg/mL was used. GABA, 5-HT, IL-1β, IL-4, and TNF-α levels and the gene expressions of GABAA-Rα1, NMDAR1, GAD 65, GAD 67, GAT 1 and GAT 3 were measured in NGF-induced PC12 cells treated with Ger (100, and 200 μg/mL). Mice were randomly separated into five groups. Normal and PTZ groups in which mice were injected with saline or PTZ, respectively. PTZ + Ger 100, PTZ + Ger 200 and PTZ + SV groups in which mice orally administered Ger or sodium valproate (SV), respectively, then injected with PTZ.

Results

Ger up to 400 μg/mL did not display any toxicity or injury in PC12 cells. Ger (100 to 200 μg/mL) reduced the injury induced by Glu, increased the gene expression of GABAA-Rα1, GAD65 and GAD67 and decreased GAT 1, GAT 3 and NMDAR1 expression in NGF-induced PC12 cells damaged by Glu. Ger (100 to 200 μg/mL) increased GABA and reduced TNF-α, IL-4 and IL-1β levels in NGF-induced PC12 cells injured by Glu. As for the in-vivo results, Ger increased GABA, GAD, GAT 1 and 3 and lowered GABA T. Ger mitigated MDA, NO, IL-1β, IL-6, TNF-α and IFN-γ, GFAP, caspase-3, and -9 levels and Bax gene expression and escalated GSH, SOD, catalase, BDNF and Bcl2 gene expression.

Conclusion

Ger reduced the oxidative stress status, neuroinflammation and apoptosis and activated GABAergic neurotransmission, which might clarify its anticonvulsant. Ger protects animals against PTZ prompted kindling as established by the enhancement in short term as well as long-term memory. Ger mitigated the injury induced by Glu in NGF prompted PC12 cell.

Selective modulation of epileptic tissue by an adenosine A3 receptor-activating drug

BACKGROUND AND PURPOSE

Adenosine, through the A1 receptor (A1R), is an endogenous anticonvulsant. The development of adenosine receptor agonists as antiseizure medications has been hampered by their cardiac side effects. A moderately A1R-selective agonist, MRS5474, has been reported to suppress seizures without considerable cardiac action. Hypothesizing that this drug could act through other than A1R and/or through a disease-specific mechanism, we assessed the effect of MRS5474 on the hippocampus.

EXPERIMENTAL APPROACH

Excitatory synaptic currents, field potentials, spontaneous activity, [3H]GABA uptake and GABAergic currents were recorded from rodent or human hippocampal tissue. Alterations in adenosine A3 receptor (A3R) density in human tissue were assessed by Western blot.

KEY RESULTS

MRS5474 (50-500 nM) was devoid of effect upon rodent excitatory synaptic signals in hippocampal slices, except when hyperexcitability was previously induced in vivo or ex vivo. MRS5474 inhibited GABA transporter type 1 (GAT-1)-mediated γ-aminobutyric acid (GABA) uptake, an action not blocked by an A1R antagonist but blocked by an A3R antagonist and mimicked by an A3R agonist. A3R was overexpressed in human hippocampal tissue samples from patients with epilepsy that had focal resection from surgery. MRS5474 induced a concentration-dependent potentiation of GABA-evoked currents in oocytes micro-transplanted with human hippocampal membranes prepared from epileptic hippocampal tissue but not from non-epileptic tissue, an action blocked by an A3R antagonist.

CONCLUSION AND IMPLICATIONS

We identified a drug that activates A3R and has selective actions on epileptic hippocampal tissue. This underscores A3R as a promising target for the development of antiseizure medications.

Chrysophanol attenuates cognitive impairment, neuroinflammation, and oxidative stress by TLR4/NFκB-Nrf2/HO-1 and BDNF/VEGF signaling in stress-intensified PTZ induced epilepsy in mice

Background

Stress is among the most common comorbid conditions with epilepsy and a strong factor in the pathophysiology of seizures. An imbalance in neuronal circuits causes recurrent unprovoked seizures in epilepsy. Dysregulation of BDNF/VEGF expression, oxidative stress, increased levels of neuroinflammatory cytokines, and increased expression of apoptotic genes contribute to the underlying cause of the seizure.

Objectives

Chrysophanol, an anthraquinone, has broad-spectrum therapeutic potential. This study evaluated the neuroprotective effect of chrysophanol with underlying pathways in PTZ-induced epilepsy with stress as a comorbid condition.

Methods

Male mice were given 35 mg/kg of PTZ every other day to induce seizures. In addition, they were exposed to 120 min of daily restraint stress for 21 days to induce stress. Chrysophanol (0.1, 1, 10 mg/kg) was administered to the mice 30 min before the PTZ in the acute study. The most effective dose (10 mg/kg) was proceeded for the chronic epilepsy model. Following this, various tests were conducted, including behavioral assessments for memory impairment and stress, analysis of antioxidant levels, histopathological and immunohistochemistry examinations, measurement of cortisol levels using ELISA, and gene expression analysis using RT-PCR.

Results

Chrysophanol demonstrated a notable decrease in both the intensity and frequency of seizures. Additionally, it effectively boosted the levels of important antioxidants such as GSH, GST, and CAT, while simultaneously reducing the levels of MDA and Nitric oxide. The histopathological analysis also showed improvement in overall morphology and survival of neurons. Chrysophanol treatment effectively showed an increase in the expression of BCL-2, and Nrf-2 with a decrease in BAX expression confirmed by immunohistochemistry. Dysregulation of vascular permeability factor, production of inflammatory cytokines, and apoptotic gene expression was successfully reversed after chrysophanol treatment analyzed through RT-PCR. Cortisol concentration was decreased in treatment groups analyzed through Enzyme-linked immunoassay. Molecular docking of chrysophanol with different proteins declared the binding affinity of the ligands with the target sites of proteins.

Conclusion

In conclusion, chrysophanol demonstrated remarkable neuroprotective and antiepileptic effects at a dose of 10 mg/kg in stress-exacerbated PTZ-induced epilepsy following the TLR4/NFκB -Nrf2/HO-1 and BDNF/VEGF pathways.

Probiotics by Modulating Gut-Brain Axis Together With Brivaracetam Mitigate Seizure Progression, Behavioral Incongruities, and Prevented Neurodegeneration in Pentylenetetrazole-Kindled Mice

BACKGROUND

The microbiota-gut-brain axis (MGBA) is a central nexus that integrates higher cognitive and emotional centers of the central nervous system (CNS) within the intricate functioning of the intestine. Accumulating evidence suggests that dysbiosis in the taxonomic diversity of gut flora plays a salient role in the progression of epilepsy and comorbid secondary complications.

METHODS

In the current study, we investigated the impact of long-term oral bacteriotherapy (probiotics; 10 mL/kg; 109 colony-forming unit/ml) as an adjunctive treatment intervention with brivaracetam (BRV; 10 mg/kg) over 21 days on pentylenetetrazole (PTZ) induced augmented epileptic response and associated electrographical and behavioral perturbations in mice. Moreover, we also unveiled antioxidant capacity and histopathologic changes in treated versus non-treated animals.

RESULTS

Results revealed combination increases seizure threshold and prevented high ictal spiking. Additionally, it alleviated PTZ-induced neuropsychiatric disturbances such as anxiety and depressive-like phenotype along with cognitive deficits. Furthermore, dual therapy prompted physiological oxidant/antioxidant balance as evidenced by increased activity of antioxidant enzymes (SOD and catalase) and reduced levels of oxidative stressor (MDA). This therapeutic intervention with commensal species suppressed network-driven neuroinflammation and preserved normal cytoarchitecture with intact morphology in the pyramidal layers of cornu ammonis (CA1 and CA3).

CONCLUSION

Our study provides supporting evidence for the use of probiotics as adjunctive therapy with anti-seizure medications to modulate epileptogenic processes and related multimorbidities, particularly in individuals with drug-resistant seizures.

Brivaracetam and rufinamide combination increased seizure threshold and improved neurobehavioral deficits in corneal kindling model of epilepsy

BACKGROUND

Besides seizures, a myriad of overlapping neuropsychiatric and cognitive comorbidities occur in patients with epilepsy, which further debilitates their quality of life. This study provides an in-depth characterization of the impact of brivaracetam and rufinamide individually and in combination at 10 and 20 mg/kg doses, respectively, on corneal kindling-induced generalized seizures and behavioral alterations. Furthermore, observed convulsive frequency and behavioral changes were correlated to post-kindling-induced changes in the activity of markers of oxidative stress.

METHODS

Adult C57BL/6 mice were kindled via twice-daily transcorneal 50-Hz electrical stimulations (3 mA) for 3 s for 12 days until animals reached a fully kindled state. After the kindling procedure, animals were tested using a set of behavioral tests, and neurochemical alterations were assessed.

RESULTS

Corneal-kindled animals exhibited intense generalized convulsions, altered behavioral phenotypes typified by positive symptoms (hyperlocomotion), negative symptoms (anxiety and anhedonia), and deficits in semantic and working memory. BRV 10 + RFM 20 dual regime increased convulsive threshold and propensity toward the start of stage 4-5 seizures and improved phenotypical deficits, that is, anxiety, depression, and memory impairments. Moreover, this combination therapy mitigated kindling-induced redox impairments as evidenced by reduced malondialdehyde and acetylcholinesterase levels and increased glutathione antioxidant activity in the brain of animals subjected to repetitive brain insult.

CONCLUSION

Based on our outcomes, this dual therapy provides supporting evidence in alleviating epilepsy-induced neurobehavioral comorbidities and changes in redox homeostasis.

Neuroprotective potential of topiramate, pregabalin and lacosamide combination in a rat model of acute SE and intractable epilepsy: Perspectives from electroencephalographic, neurobehavioral and regional degenerative analysis

The lithium-pilocarpine model is commonly used to recapitulate characteristics of human intractable focal epilepsy. In the current study, we explored the impact of topiramate (TPM) alone and in combination with pregabalin and lacosamide administration for 6 weeks on the evolution of spontaneous recurrent seizures (SRS) and disease-modifying potential on associated neuropsychiatric comorbidities. In addition, redox impairments and neurodegeneration in hippocampus regions vulnerable to temporal lobe epilepsy (TLE) were assessed by cresyl violet staining. Results revealed that acute electrophysiological (EEG) profiling of the ASD cocktail markedly halted sharp ictogenic spikes as well as altered dynamics of brain wave oscillations thus validating the need for polytherapy vs. monotherapy. In TLE animals, pharmacological intervention for 6 weeks with topiramate 10 mg/kg in combination with PREG and LAC at the dose of 20 mg/kg exhibited marked protection from SRS incidence, improved body weight, offensive aggression, anxiety-like behavior, cognitive impairments, and depressive-like behavior (p < 0.05). Moreover, combination therapy impeded redox impairments as evidenced by decreased MDA and AchE levels and increased activity of antioxidant SOD, GSH enzymes. Furthermore, polytherapy rescued animals from SE-induced neurodegeneration with increased neuronal density in CA1, CA3c, CA3ab, hilus, and granular cell layer (GCL) of the dentate gyrus. In conclusion, early polytherapy with topiramate in combination with pregabalin and lacosamide prompted synergy and prevented epileptogenesis with associated psychological and neuropathologic alterations.

Discovery and Profiling of New Multimodal Phenylglycinamide Derivatives as Potent Antiseizure and Antinociceptive Drug Candidates

We developed a focused series of original phenyl-glycinamide derivatives which showed potent activity across in vivo mouse seizure models, namely, maximal electroshock (MES) and 6 Hz (using both 32 and 44 mA current intensities) seizure models. Following intraperitoneal (i.p.) administration, compound (R)-32, which was identified as a lead molecule, demonstrated potent protection against all seizure models with ED50 values of 73.9 mg/kg (MES test), 18.8 mg/kg (6 Hz, 32 mA test), and 26.5 mg/kg (6 Hz, 44 mA test). Furthermore, (R)-32 demonstrated efficacy in both the PTZ-induced kindling paradigm and the ivPTZ seizure threshold test. The expression of neurotrophic factors, such as mature brain-derived neurotrophic factor (mBDNF) and nerve growth factor (NGF), in the hippocampus and/or cortex of mice, and the levels of glutamate and GABA were normalized after PTZ-induced kindling by (R)-32. Importantly, besides antiseizure activity, (R)-32 demonstrated potent antinociceptive efficacy in formalin-induced pain, capsaicin-induced pain, as well as oxaliplatin- and streptozotocin-induced peripheral neuropathy in mice (i.p.). No influence on muscular strength and body temperature in mice was observed. Pharmacokinetic studies and in vitro ADME-Tox data (i.e., high metabolic stability in human liver microsomes, a weak influence on CYPs, no hepatotoxicity, satisfactory passive transport, etc.) proved favorable drug-like properties of (R)-32. Thermal stability of (R)-32 shown in thermogravimetry and differential scanning calorimetry gives the opportunity to develop innovative oral solid dosage forms loaded with this compound. The in vitro binding and functional assays indicated its multimodal mechanism of action. (R)-32, beyond TRPV1 antagonism, inhibited calcium and sodium currents at a concentration of 10 μM. Therefore, the data obtained in the current studies justify a more detailed preclinical development of (R)-32 for epilepsy and pain indications.

Saccharomyces Boulardii alleviates neuroinflammation and oxidative stress in PTZ-kindled seizure rat model

Previous research have reported that modulating the gut microbiome composition by fecal microbiota transplantation and probiotic administration can alleviate seizure occurrence and severity. Saccharomyces boulardii (SB) is a yeast probiotic that has demonstrated ameliorating effects on anxiety, memory and cognitive deficit, and brain amyloidogenesis. In this research, our goal was to examine the anti-seizure effects of SB on the pentylenetetrazole (PTZ)-kindled male Wistar rats. The animals were randomly categorized into four test groups. The rats were orally administered with saline (control and PTZ groups) or S. boulardii (SB + PTZ and SB groups) for 57 days. From the 29th day of the experiment, the animals received intraperitoneally saline (control and SB groups) or PTZ (PTZ and SB + PTZ groups) on alternate days for 30 days. The administration dose of SB and PTZ was 1010 CFU/ml/day and 35 mg/kg, respectively. We assessed animal seizure behavior, neuroinflammation, oxidative stress, and the levels of matrix metalloproteinase-9 (MMP-9) and brain-derived neurotrophic factor (BDNF) in the hippocampus tissue. S. boulardii hindered the PTZ-induced kindling development. SB treatment elevated glutathione (GSH) and total antioxidant capacity (TAC) and reduced malondialdehyde (MDA) levels. SB also lessened the hippocampal levels of BDNF and MMP-9. Following SB supplementation, proinflammatory cytokines interleukin-1 beta (IL-1β) and IL-6 were lowered, and anti-inflammatory cytokine IL-10 was enhanced. Overall, our data indicated, for the first time, the positive impact of SB on the PTZ-kindled seizure rat model. The anti-seizure activity of SB was mediated by modulating oxidative stress, neuroinflammation, and MMP-9 and BDNF levels.

Ways of modulating GABA transporters to treat neurological disease

INTRODUCTION

The main inhibitory neurotransmitter in the central nervous system (CNS), γ-aminobutyric acid (GABA), is involved in a multitude of neurological and psychiatric disorders characterized by an imbalance in excitatory and inhibitory signaling. Regulation of extracellular levels of GABA is maintained by the four GABA transporters (GATs; GAT1, GAT2, GAT3, and BGT1), Na+/Cl--coupled transporters of the solute carrier 6 (SLC6) family. Despite mounting evidence for the involvement of the non-GAT1 GABA transporters in diseases, only GAT1 has successfully been translated into clinical practice via the drug tiagabine.

AREAS COVERED

In this review, all four GATs will be described in terms of their involvement in disease, and the most recent data on structure, function, expression, and localization discussed in relation to their potential role as drug targets. This includes an overview of various ways to modulate the GATs in relation to treatment of diseases caused by imbalances in the GABAergic system.

EXPERT OPINION

The recent publication of various GAT1 structures is an important milestone for future development of compounds targeting the GATs. Such information can provide much needed insight into mechanistic aspects of all GAT subtypes and be utilized to design improved ligands for this highly interesting drug target class.

Neuroprotective Effect of Brivaracetam and Perampanel Combination on Electrographic Seizures and Behavior Anomalies in Pentylenetetrazole-Kindled Mice

Pentylenetetrazole (PTZ)-induced kindling is a broadly used experimental model to study the anticonvulsive potential of new and existing chemical moieties with the aim of discovering drugs hindering seizure progression and associated neurological comorbidities. In the present study, the impact of brivaracetam (BRV) (10 and 20 mg/kg) as monotherapy as well as in combination with 0.25 mg/kg of perampanel (PRP) was investigated on seizure progression with simultaneous electroencephalographic changes in PTZ kindling mouse model. Subsequently, mice were experimentally analyzed for anxiety, cognition, and depression after which their brains were biochemically evaluated for oxidative stress. The outcomes demonstrated that BRV alone delayed the kindling process, but BRV + PRP combination significantly (p < 0.0001) protected the mice from seizures of higher severity and demonstrated an antikindling effect. The PTZ-kindled mice exhibited anxiety, memory impairment, and depression in behavioral tests, which were remarkably less (p < 0.001) in animals treated with drug combination (in a dose-dependent manner) as these mice explored central, illuminated, and exposed zones of open-field test, light/dark box, and elevated plus maze. Moreover, memory impairment was demonstrated by kindled mice, which was significantly (p < 0.001) protected by BRV + PRP as animal's spontaneous alteration, object discrimination, and step-through latencies were increased in various tests employed for the assessment of cognitive abilities. The brains of PTZ-kindled mice had increased malondialdehyde and reduced antioxidant enzymes while treatment with BRV + PRP combination prevented kindling-induced elevation in oxidative markers. The outcomes of this study demonstrate that combining the PRP at low dose augmented the antiseizure properties of BRV as both drugs when administered simultaneously hindered the process of kindling by reducing PTZ-induced excessive electrical activity and oxidative stress in the brain.

Ameliorative effect of Nyctanthes arbor-tristis L. by suppression of pentylenetetrazole-induced kindling in mice: An insight from EEG, neurobehavioral and in-silico studies

Epilepsy is an abiding condition associated with recurrent seizure attacks along with associated neurological and psychological emanation owing to disparity of excitatory and inhibitory neurotransmission. The current study encompasses the assessment of the Nyctanthes arbor-tristis L. methanolic extract (Na.Cr) in the management of convulsive state and concomitant conditions owing to epilepsy. The latency of seizure incidence was assessed using pentylenetetrazol (PTZ) kindling models along with EEG in Na.Cr pretreated mice, trailed by behavior assessment (anxiety and memory), biochemical assay, histopathological alterations, chemical profiling through GCMS, and molecular docking. The chronic assessment of PTZ-induced kindled mice depicted salvation in a dose-related pattern and outcomes were noticeable with extract at 400 mg/kg. The extract at 400 mg/kg defends the progress of kindling seizures and associated EEG. Co-morbid conditions in mice emanating owing to epileptic outbreaks were validated by behavioral testing and the outcome depicted a noticeable defense related to anxiety (P<0.001) and cognitive deficit (P<0.001) at 400 mg/kg. The isolated brains were evaluated for oxidative stress and the outcome demonstrated a noticeable effect in a dose-dependent pattern. Treatment with Na.Cr. also preserved the brain from PTZ induced neuronal damage as indicated by histopathological analysis. Furthermore, the GCMS outcome predicted 28 compounds abundantly found in the plant. The results congregated in the current experiments deliver valued evidence about the defensive response apportioned by Na.Cr which might be due to decline in oxidative stress, AChE level, and GABAergic modulation. These activities may contribute to fundamental pharmacology and elucidate some mechanisms behind the activities of Nyctanthes arbor-tristis.

Barbaloin Protects Pentylenetetrazol-Induced Cognitive Deficits in Rodents via Modulation of Neurotransmitters and Inhibition of Oxidative-Free-Radicals-Led Inflammation

BACKGROUND

Epilepsy is defined by an excessive level of activity in the neurons and coordinated bursts of electrical activity, resulting in the occurrence of seizure episodes. The precise cause of epileptogenesis remains uncertain; nevertheless, the etiology of epilepsy may involve neuroinflammation, oxidative stress, and malfunction of the neurotransmitter system.

OBJECTIVE

The goal of this investigation was to assess barbaloin's protective properties with respect to pentylenetetrazol (PTZ)-)-induced cognitive deficits in rats via antioxidative, anti-inflammatory, and neurotransmitter-modulating effects.

METHODS

Wistar rats were subjected to PTZ [40 mg/kg (i.p.)], which induced cognitive decline. Behavior assessment using a kindling score, open-field test (OFT), novel object recognition test (NORT), and assays for superoxide dismutase (SOD), reduced glutathione (GSH), catalase (CAT), malondialdehyde (MDA), acetylcholinesterase (AChE), caspase-3, nitric oxide (NO), interleukins-1β (IL-1β), tumor necrosis factor-α (TNF-α), IL-6, nuclear factor kappa-B (NF-κB), Bcl-2 and Bax, and neurotransmitter levels [GABA, DA, NE, and serotonin (5-HT)] were performed.

RESULTS

The treatment of rats with barbaloin resulted in behavior improvement and significant changes in the levels of GSH, SOD, CAT, MDA, AChE, NO, IL-6, IL-1β, TNF-α, NF-κB, caspase-3, Bcl-2, and Bax compared to the PTZ control group. Barbaloin treatment resulted in notable changes in neurotransmitter levels (GABA, NE, 5-HT, DA) compared to the PTZ group.

CONCLUSIONS

The ongoing study has gathered evidence indicating that the injection of barbaloin has resulted in significant improvements in cognitive performance in rats. This is achieved by inhibiting oxidative stress, enhancing the activity of natural antioxidant enzymes, reducing cytokine levels, and increasing the levels of neurotransmitters in the brain. These results were detected in comparison to a PTZ control and can be attributed to the potent anti-inflammatory and antioxidant capabilities of barbaloin, which could be linked to its neuroprotective properties. Barbaloin may potentially increase cognitive decline and boost neuronal survival by altering the expression of Bax, caspase-3, Bcl-2.

Therapeutic benefits of quercetin in traumatic brain injury model exposed to cigarette smoke

Scientific evidences reported the deleterious effect of cigarette smoking or passive smoking on brain health particularly cognitive functions, blood-brain barrier (BBB) permeability, up-regulation of inflammatory cascades, and depletion of the antioxidant system. These combined effects become more progressive in the events of stroke, traumatic brain injury (TBI), and many other neurodegenerative diseases. In the current study, we investigated the long-term administered therapeutic potential of quercetin in ameliorating the deleterious neurobiological consequences of chronic tobacco smoke exposure in TBI mice. After exposure to 21 days of cigarette smoke and treatment with 50 mg/kg of quercetin, C57BL/6 mice were challenged for the induction of TBI by the weight drop method. Subsequently, a battery of behavioral tests and immunohistochemical analyses revealed the beneficial effect of quercetin on the locomotive and cognitive function of TBI + smoked group mice (p < 0.05 vs control sham). Immunohistochemistry analysis (Nrf2, HO-1, NFkB, caspase 3) demonstrated a marked protection after 21 days of quercetin treatment in the chronic tobacco smoking group possibly by up-regulation of antioxidant pathways, and decreased apoptosis. In conclusion, our findings support the therapeutic effectiveness of quercetin in partly protecting the central neurological functions that become aberrantly impaired in combined habitual cigarette-smoking individuals impacted with TBI.

Unveiling the potential of perampanel and pregabalin in addressing pentylenetetrazole-induced electrographic alterations and neurobehavioral anomalies

Chemical kindling is broadly used experimental model to investigate novel treatments on the process of epileptogenesis and coexisting behavioral comorbidities. The current study aimed to investigate the low dose perampanel (PER) (0.125 and 0.5 mg/kg) and pregabalin (PG) (15 mg/kg) as standalone treatments and in combination on kindling-induced seizure progression with concurrent electroencephalographic alterations. Mice were subjected to pentylenetetrazole (PTZ)-induced kindling followed by neurobehavioral assessment for anxiety-like activity and cognitive deficit through behavioral experiments. The monotherapy with PER at 0.5 mg/kg and PG at 15 mg/kg delayed the kindling process but PRP+PG yielded pronounced benefits and hindered the development of seizures of higher severity. PER+PG combination relieved the animals from anxiety-like behavior in various employed anxiogenic tests. Furthermore, the kindling-associated cognitive deficit was protected by PER+PG combination as increased alteration behavior, discrimination index and latencies to enter the dark zone were noted in y-maze, object recognition and passive avoidance tests, respectively while shorter escape latencies were noted in water maze. The brain samples of kindled mice had elevated malondialdehyde and reduced catalase, superoxide dismutase and glutathione peroxidase enzymes while treatment with PER and PG combination shielded the mice from heightened kindling-associated oxidative stress. Overall, the findings of the present study illustrate that concurrent administration of PER and PG effectively hindered the process of epileptogenesis by protecting neuronal excitability and brain oxidative stress. The results predict the dominance of PER and PG combination over monotherapy which might serve as an effective novel combination to combat drug resistance and behavioral disorders in epileptic patients.

Perampanel increases seizure threshold in pentylenetetrazole-kindled mice and improves behavioral dysfunctions by modifying mRNA expression levels of BDNF/TrkB and inflammatory markers

Perampanel (PER), a novel 3rd-generation antiseizure drug that modulates altered post-synaptic glutamatergic storming by selectively inhibiting AMPA receptors, is recently approved to treat intractable forms of seizures. However, to date, presumably consequences of long-term PER therapy on the comorbid deleterious psychiatric disturbances and its correlation with neuroinflammatory parameters are not fully investigated in chronic models of epilepsy. Therefore, we investigated the real-time effect of PER on brain electroencephalographic (EEG) activity, behavioral alterations, redox balance, and relative mRNA expression in pentylenetetrazole (PTZ) induced kindling. Male BALB/c mice were pretreated with PER (0.125, 0.25, and 0.5 mg/kg) for 3 weeks and challenged with 11 injections of PTZ at the sub-threshold dose of 40 mg/kg every other day. vEEG from implanted cortical electrodes was monitored to elucidate seizure propagation and behavioral manifestations. Recorded EEG signals exhibited that PER 0.5 mg/kg pretreatment exceptionally impeded the onset of sharp epileptic spike-wave discharges and associated motor symptoms. Additionally, qEEG analysis showed that PER prevented alterations in absolute mean spectral power and reduced RMS amplitude of epileptogenic spikes vs PTZ control. Furthermore, our outcomes illustrated that PER dose-dependently attenuated PTZ-evoked anxiety-like behavior, memory deficits, and depressive-like behavior that was validated by a series of behavioral experiments. Moreover PER, significantly reduced lipid peroxidation, AChE, and increased levels of SOD and total thiol in the mice brain via AMPAR antagonism. Post-PTZ kindling provoked overstimulation of BDNF/TrkB signaling and increased release of pro-inflammatory cytokines that were reversed by PER with suppression of iNOS in brain immune cells. In conclusion, our findings highlight that PER might play an auspicious preventive role in the proepileptic transformation of brain circuits via suppression of BDNF/TrkB signaling and reduced transcriptional levels of neuroinflammatory markers leading to improvised epilepsy-induced neurobehavioral and neurochemical effects.

Seizure susceptibility to various convulsant stimuli in the BTBR mouse model of autism spectrum disorders

Background: Autism spectrum disorders (ASDs) are one of the most severe chronic childhood disorders in terms of prevalence, morbidity, and impact on society. Interestingly, several systematic reviews and meta-analyses documented a bidirectional link between epilepsy and ASD, supporting the hypothesis that both disorders may have common neurobiological pathways. According to this hypothesis, an imbalance of the excitatory/inhibitory (E/I) ratio in several brain regions may represent a causal mechanism underpinning the co-occurrence of these neurological diseases. Methods: To investigate this bidirectional link, we first tested the seizure susceptibility to chemoconvulsants acting on GABAergic and glutamatergic systems in the BTBR mice, in which an imbalance between E/I has been previously demonstrated. Subsequently, we performed the PTZ kindling protocol to study the impact of seizures on autistic-like behavior and other neurological deficits in BTBR mice. Results: We found that BTBR mice have an increased susceptibility to seizures induced by chemoconvulsants impairing GABA_A neurotransmission in comparison to C57BL/6J control mice, whereas no significant difference in seizure susceptibility was observed after administration of AMPA, NMDA, and Kainate. This data suggests that deficits in GABAergic neurotransmission can increase seizure susceptibility in this strain of mice. Interestingly, BTBR mice showed a longer latency in the development of kindling compared to control mice. Furthermore, PTZ-kindling did not influence autistic-like behavior in BTBR mice, whereas it was able to significantly increase anxiety and worsen cognitive performance in this strain of mice. Interestingly, C57BL/6J displayed reduced sociability after PTZ injections, supporting the hypothesis that a tight connection exists between ASD and epilepsy. Conclusion: BTBR mice can be considered a good model to study epilepsy and ASD contemporarily. However, future studies should shed light on the mechanisms underpinning the co-occurrence of these neurological disorders in the BTBR model.